School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, P. R. China.
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen, 361005, P. R. China.
Chemistry. 2019 Apr 1;25(19):5036-5042. doi: 10.1002/chem.201805941. Epub 2019 Mar 12.
The use of Li metal as the anode for Li-based batteries has attracted considerable attention due to its ultrahigh energy density. However, the formation of Li dendrites, uneven deposition, and huge volume changes hinder its reliable implementation. These issues become much more severe in commercial carbonate-based electrolytes than in ether-based electrolytes. Herein, a rationally designed three-dimensional graphene/Ag aerogel (3D G-Ag aerogel) is proposed for Li metal anodes with long cycle life in carbonate-based electrolytes. The modified lithiophilic nature of G-Ag aerogel, realized through decoration with Ag NPs, effectively decreases the energy barrier for Li nucleation, regulating uniform Li deposition behavior. Moreover, the highly flexible, conductive 3D porous architecture with hierarchical mesopores and macropores can readily accommodate deposited Li and ensures the integrity of the conductive network during cycling. Consequently, high coulombic efficiency (over 93.5 %) and a significantly long cycle life (1589 h) over 200 cycles, with a relatively high cycling capacity of 2.0 mAh cm , can easily be achieved, even in a carbonate-based electrolyte. Considering the intrinsic high voltage windows of carbonate-based electrolytes, matching the G-Ag aerogel Li metal anode with a high-voltage cathode can be envisaged for the fabrication of high-energy-density Li secondary batteries.
由于其超高的能量密度，将金属锂用作基于锂的电池的阳极引起了相当大的关注。然而，锂枝晶的形成、不均匀的沉积和巨大的体积变化阻碍了其可靠的实施。在基于碳酸盐的电解质中，这些问题比基于醚的电解质更为严重。在此，提出了一种合理设计的三维石墨烯/Ag 气凝胶（3D G-Ag 气凝胶），用于在基于碳酸盐的电解质中具有长循环寿命的锂金属阳极。通过 Ag NPs 修饰实现的 G-Ag 气凝胶的改性亲锂性质，有效降低了 Li 成核的能量势垒，调节了均匀的 Li 沉积行为。此外，具有分级介孔和大孔的高度灵活、导电的 3D 多孔结构可以轻松容纳沉积的 Li，并确保在循环过程中导电网络的完整性。因此，即使在基于碳酸盐的电解质中，也可以轻松实现高库仑效率（超过 93.5%）和显著长的循环寿命（200 次循环超过 1589 h），具有相对较高的循环容量 2.0 mAh cm 。考虑到基于碳酸盐的电解质的固有高压窗口，可以与 G-Ag 气凝胶锂金属阳极匹配高电压阴极，用于制造高能量密度的锂二次电池。
